Outdoors: Itching for poison ivy relief

Thursday

Sep 23, 2010 at 12:01 AMSep 23, 2010 at 11:22 PM

With the end of summer, a lot of people are out enjoying the cooler weather. This means, unfortunately, it’s also the time of the year when we have the best chances of coming in contact with poison ivy.

Jeff Brown, News Editor

With the end of summer, a lot of people are out enjoying the cooler weather and clearing land in preparation for the winter season.

This means, unfortunately, it’s also the time of the year when we have the best chances of coming in contact with poison ivy. The plant can grow in different varieties: as a bush, a vine or attached to trees.

Poison ivy is best identified by its shiny three-lobed leaves –– hence the reminder, “Leaves of three, let them be.” Just a little contact with the oils on the leaves can cause skin reactions ranging from slightly annoying to incredibly irritating, according to Dr. Joseph F. Andrews at Delaware Dermatology.

Andrews took a few minutes to talk about this nuisance plant: how its poison works and how to best get relief from the rash and itching.

1. Why does poison ivy give people so much trouble?

“It’s the fat from the plant,” Andrews said. “When it comes in contact with skin, it causes an allergic reaction.”

The scientific designation for the poison ivy bush is toxicodendron radicans, which is Greek for “poison tree.” That name itself should serve as a warning that the plant has noxious qualities. The fat, known as urushiol, is contained in the plant’s sap and coats its leaves.

Urushiol causes the rash, blisters and skin eruptions that develop after contact with the plant, says Andrews. People most commonly see it when they unknowingly walk through a patch of the plant, causing red streaks across the legs. (That’s one good reason why not to wear shorts while trekking through the woods.)

2. You don’t have to touch it to get it.

“You may have heard this in Boy Scouts, and I didn’t believe it back then, but you can walk right past poison ivy and get [a reaction from] it,” said Andrews.

That’s particularly true if you’re out on a windy day. The wind picks up minute droplets of the urushiol and blows them through the air. If they land on your skin, you’ll have an allergic reaction.

The phenomenon is called airborne dermatitis. Because the urushiol is particularly hardy, people also can get it on their skin, or inhale it, if they even burn contaminated wood, said Andrews.

“The thing is, if the resin gets in the wood, it can stay there,” Andrew said. “When it burns, it aerosolizes and, if you’re exposed, you can get airborne dermatitis.”

In addition, people can pick up the oils from animals, especially if the family dog has been cavorting in the woods. The oil can rub off on their fur and humans can pick it up when handling the dogs. The same cautions apply when handling clothing that may have been exposed to urushiol, as the oil can rub off on the hands.

3. It’s important to act quickly if exposed to poison ivy.

The best thing to do is not come in contact with the plants at all. In addition to wearing long pants, people should wear long sleeves and consider wearing gloves, especially if clearing land where poison ivy may be present. A hat will prevent scalp exposure and safety goggles can help keep the urushiol from getting in the eyes.

Eventually, if you come in contact with poison ivy and leave it untreated, it will cause large blisters to form. The agony is made only worse when the blisters start to ooze. But reacting quickly is essential to preventing the worst of the problems.

“If you’re exposed to the allergen, you have about 10 minutes to wash it off,” he said. “If you go in quick and wash with soap and water, there’s a pretty good chance you won’t react. Ten minutes or longer, the chances are you will.”

4. Treatment of poison ivy contact can vary.

Most symptoms appear within 24 hours of exposure. A lot of people use calamine lotion, which helps soothe irritated skin, but that treats only the symptoms, not the underlying cause, says Andrews. Hydrocortisone creams also are good in mild cases of urushiol exposure, but they aren’t as effective for severe cases.

Other home remedies include taking Benedryl to help treat the itching, plus cool compresses, which also help with the skin irritation.

There are other prescription-strength medications that help. In more complicated cases, topical or even oral steroids can help.

“Your problem will improve while you’re on the medication, but when you’re off it, the problem can get worse. That’s a rebound phenomenon. The biggest problem is some people are not treated with high enough doses for a long enough time.”

5. Some people are more sensitive to poison ivy than others.

Poison ivy’s urushiol oil is extremely potent, and it only takes one nanogram (a billionth of a gram) to cause a rash. Even if you’ve never broken out, you can’t assume that you are immune to poison ivy. In fact, the more often you are exposed to urushiol, the more likely it is that you will break out with an allergic rash.

Depending on sensitivity to the urushiol, some people may see little or no effect, while others may have what Andrews calls a “rip-roaring reaction.” However, than 90 percent of the population develops an allergy to poison ivy.